Working server-side inventory. And as a result of that, a whole pile of bugs and issues got fixed.

Made SMP servers save chunks way less often in most cases. Chunks don't resave if they got saved in the last 30 seconds.

Moving too far away from a container, or having it blow up, closes the inventory screen.

Fixed /kill.

Introduced leaf decay again. It acts differently from before, as it now drops the saplings from the leaves.

You can now throw eggs.

Throwing an egg has a chance of spawning a chicken.

Added super exclusive clan cloaks for Mojang Employees.

When you mouse over a block, a tooltip appears (its name pops up in a box).

You can't store things in the inventory crafting blocks anymore.

Something else, which is even more rare.

There's a serious problem getting the client started for some people (especially Mac OSX?). I've also heard about weird item duplication bugs with dropped items, and a severe performance reduction.
I will work on these bugs tomorrow.

I'm also hoping to be able to squeeze in some fun for christmas. Perhaps a new mob?

Reindeers! When you kill them, they have a rare chance of spawning a red nose. (For what reason, I don't know xP) and a chance of spawning a present. (That contain something special or a random item drop when you open it.) Reindeers are situated in snow areas in higher mountains. That's my suggestion. :P

Ugh, now that beta is here, it lags like hell. I'm not gonna play for a while so i don't waste my life on a game that originally ran as smoothly as a small flash game, but now runs like gmod right before i crash the game.